An EgyptAir flight en route from Paris to Cairo has gone missing with 56 passengers and 10 crewmembers on board. While a search and rescue operation is under way, authorities and experts say no scenario can be ruled out, including terrorism.

Flight MS804, an Airbus 320, left Charles de Gaulle Airport in Paris at 11:09 p.m. local time (2109 GMT) on Wednesday and was expected to arrive in Cairo by 03:00 a.m. Thursday. A direct flight usually takes just over four hours. It went off radar screens just as it was leaving Greek airspace at 0230 GMT.

French President Francois Hollande confirmed that the missing plane had crashed, and added that “no hypothesis” could be ruled out on the causes of the incident. Speaking in a televised address, he offered “solidarity” with the families of those on board.

"It could be a terrorist hypothesis but at this stage we should express our solidarity to the families and to find out the cause of the catastrophe," Hollande said.

The possibility of a terrorist attack is more likely than a technical failure, Egyptian Aviation Minister Sherif Fathy said at a media conference in Cairo on Thursday.

According to the Greek Defense Ministry, the plane made “sudden swerves” just before going off radar.

"At 03:39 a.m. the course of the aircraft was south and southeast of Kassos and Karpathos (islands). Immediately after it entered Cairo FIR and made swerves and a descent I describe – 90 degrees left and then 360 degrees to the right," Defense Minister Panos Kammenos told a news conference.

EgyptAir has published information about the nationalities of the 56 passengers. It lists 30 Egyptians, 15 French, two Iraqis and one citizen each from the UK, Belgium, Kuwait, Saudi Arabia, Sudan, Chad, Portugal, Algeria and Canada.

The Egyptian crew included two cockpit crew, five cabin crew and three security officers.

about 280 KM from the Egyptian seacoast at 02:30 am CLT as the flight was expected to arrive Cairo Airport at 03:15 am CLT.

French and Egyptian authorities offered their assistance to family members of the passengers and crewmembers of the missing plane. EgyptAir provided a plane to fly relatives from France to Egypt, while an emergency center was opened at Charles de Gaulle Airport.

A search and rescue operation involving Egyptian, Greek and French military aircraft and ships and a number of civilian vessels is under way in the southern Mediterranean. Hours into the operation, the Greeks reportedly found two objects floating in the sea 50 miles southeast of the area where the plane dropped off radar.

EgyptAir described the captain of the plane as experienced, with over 6,275 flying hours, including 2,101 hours flying Airbus 320s, while his co-pilot has 2,766 hours. The aircraft was manufactured in 2003.

In 2013, the missing A320 reportedly experienced engine failure, SkyNews Arabia said citing an Egyptian civil aviation source. At that time, the aircraft was scheduled to fly from Cairo to Istanbul, but had to return for an emergency landing. The airline said the plane was in good technical condition and passed all necessary checks.

Some media reports in Greece said a vessel witnessed a flash in the sky sometime around the moment of the plane’s disappearance, but the information could not be confirmed. Reports in Egypt said a distress call was received by the Egyptian military from the plane before it went missing, but the Egyptian authorities would not confirm them.

The crew on board the plane didn’t report to Greek traffic controllers any problems before leaving the Athens Flight Information Region. The Greek controllers said the pilot was in good humor and thanked them in Greek just as the plane was supposed to be handed over to their colleagues in Cairo.

We are aware of media reports. At this time we have no further details, but we will provide further information when available.

In March, an EgyptAir domestic flight MS181 from Alexandria to Cairo was hijacked in mid-air by one of the passengers and diverted to Larnaca, Cyprus, with 81 people on board. After a six-hour standoff, the hijacker, Seif Eldin Mustafa, released the passengers and crew, and surrendered to Cypriot police.

Paris’s Charles de Gaulle Airport has seen hundreds of flights to, from and over Paris canceled due to a massive strike by air traffic controllers and ground staff. They are taking part in a nationwide strike to protest the new labor reform proposed by the French government that takes away workers’ rights.